A halo nevus occurs when the body develops an immune response to the pigment cells around a nevus. The pigment disappears and the area becomes white. Often in the process, the nevus itself disappears, leaving a circular white spot (macula).
Reviewed last on: 7/17/2007
Kevin Berman, MD, PhD, Associate, Atlanta Center for Dermatologic Disease, Atlanta, GA. Review provided by VeriMed Healthcare Network.